Allow setting modal size when registering a custom picker component

[julien-nc]

Design review outcome: Some custom picker components don't look good in a "large" NcModal.

This allows to pass the desired modal size when registering a custom picker component.
This size is then used by NcReferencePickerModal.

[AndyScherzinger]

/backport to stable7

[juliushaertl]

@julien-nc Max/Jonas are out today, do you have an app that can be used for testing this already around so we can pull in someone else for another review today?

[Antreesy]

Seems fine by code, but didn't tested it yet

[mejo-]

Code changes look good to me. Didn't test locally though.

[julien-nc]

@juliushaertl Any app implementing a custom smart picker component:

• integration_giphy
• integration_openstreetmap
• integration_openai
• integration_replicate
• text_templates
• files

For testing this properly:

• the component registration must be done with this nc/vue branch
• the modal size must be passed when registering (already done in most of the apps mentioned)
• the app showing the smart picker should also use this nc/vue branch